First wallpaper: too many focal points; try removing the wing brushes on the lower right and left (the ones that look
like they're on Color Dodge). I'm a bit on the fence about the musical notation brushes, I personally
don't like them but they kinda work; I'd suggest changing the font to something more grungy looking (Google
"grunge fonts" and you'll find a ton). And, um, this is probably a personal preference thing, but the
wings on him look really corny - also, since he's bent over a bit, the wings shouldn't be so straight (you
should also rotate them towards the right).
Second wallpaper: this is my favorite of all three, thanks to the colors. Good job on it! Only thing I'd suggest is
(again) changing the font on "Cause my life is music" and "Let's play", since system(-looking)
fonts are almost always a bad idea. Other than that, the brushes work surprisingly well!
Third wallpaper: too many dusty hues. The guy's colors are contrasting (black & white), while your background
is "dull" in comparison. Try to include some black or white in it. Again, there are too many focal points
because you added too many shapes in random spots. I know the norm for these walls is going crazy with the shapes, but
they're generally placed behind the character so as to draw attention to him (I know you were going for the arrows pointing towards him, but it doesn't work, IMO). And I
think the wall look better without the grungy textures, since they make the guy look even more separated from the
background.
P.S. regarding the other link, the latest version you posted is just a thumbnail.